To log in to the Gear Store you must have a Gear Store account different from your Battle.net account.
How to block communication from another player in Diablo III.
Troubleshooting for error 315000
These errors can be caused by temporary server issues in a specific region.
Troubleshooting for unresponsive mouse cursor issues in Diablo III
Troubleshooting steps for resolving lock ups in Diablo III.
Troubleshooting steps to help you connect to Diablo III
Enabling the Command Key + Click combination on Mac systems.
How to report a bug in Diablo III